Currently, many media editing applications for creating media presentations exist that composite several pieces of media content such as video, audio, animation, still image, etc. Such applications give graphical designers, media artists, and other users the ability to edit, combine, transition, overlay, and piece together different media content in a variety of manners to create a resulting composite presentation. Examples of media editing applications include Final Cut Pro® and iMovie®, both sold by Apple® Inc.
The media editing applications include a graphical user interface (“GUI”) that provides different tools for creating and manipulating media content. These tools include different controls for changing the volume of audio for different media contents. One way of changing the audio volume is to display a waveform that plots the audio levels as a function of time and provide a control to change the relative level of the audio. Some GUIs display a volume bar on the audio waveform and allow the user to change the volume by dragging the volume bar up or down by a relative value. For instance, by moving the volume bar from −7 decibels (dB) to −5 dB the volume of the audio is increased by 2 dB.
This method of changing the volume has several shortcomings. For instance, even after the maximum allowed adjustment, the volume of a quiet clip might not become loud enough. On the other hand, a clip with a loud peak might be clipped off if the volume is raised by a relative value that makes the peak go beyond the maximum allowed level. In addition, in a non-linear volume scale, changes to the volume bar and the resulting changes to the corresponding waveform do not move in locked step.
Additionally, when portions of an audio clip have different loudness, using a single volume bar to adjust the volume of the audio clip does not allow fine tuning of the volume in different portions of the clip. Similarly, when an audio clip or a portion of an audio clip is displayed with low volume, visually identifying different points such as maximum points and minimum points (or the peaks and valleys) of the clip and aligning them to each other or to a specific time on a displayed timeline is difficult.